1. Field of the Invention
The present invention relates generally to hand-held trimming knives of the type which utilize a disposable razor blade for its cutting edge. More specifically, the invention relates to such a trimming knife which is specifically adapted for riding along the edge of the picture frame for trimming a paper dust cover applied over its rear surface.
2. Description of Related Art
Lafever et al. U.S. Pat. No. 1,908,851 shows a safety razor carton opener having a base plate having a step at one edge so as to form a flange on one side of the base. Bars project upwardly from the base for enabling the slot of a safety razor blade mounted over the bars so that they will be carried on the base at an acute angle to the step. A cover plate is applied onto the blade and bars and is held in place by a screw and wingnut assembly. While intended to be held in the hand of the user, the configuration of this trimmer is not designed to facilitate such use since its essentially block-like shape cannot be easily or comfortably held in a user's hand. Additionally, this trimmer is limited to use with appropriately slotted razor blades and the acute angle orientation of the single blade precludes the device from being used to trim in either direction of movement, up and back, or from being used in either hand without repositioning the blade from one set of bars to the other.
Also, a wallpaper trimmer is disclosed in U.S. Pat. No. 4,667,409 to D'Amato which consists of two blocks secured together by two screws to create a step at one edge and having a pair of angled cutting blades clamped between them. Like the trimmer of Lafever, this trimmer is intended to be held in the hand of the user, but the essentially block-like shape of the trimmer prevents it from being easily or comfortably held in a user's hand. While the oppositely acute angled pair of blades may be intended to allow ambidextrous use of the cutter in an up and back cutting motion with wall paper, if used to trim thin paper as used for the dust cover backing on picture frames, the point of the one of the blades which is facing away from the direction of motion can puncture and rip the paper.
Thus, there is still a need for a hand-held razor trimming device which can be comfortable held in either hand, and can cut in either direction of an up-and-back motion without fear of ripping even thin papers.